[IAUC] IAUC 8945: C/2008 J6; C/2007 W1 [25139-2008/05-R1]

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                                                  Circular No. 8945
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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COMET C/2008 J6 (HILL)
     R. E. Hill reports his discovery of a comet with a diffuse
coma but a clear nuclear condensation and a fan-shaped tail 1' long
in p.a. 210 deg on four co-added 30-s Catalina Sky Survey exposures
obtained in 2"-4" seeing with the 0.68-m Schmidt telescope
(discovery observation tabulated below).  Following posting on the
'NEOCP' webpage, J. C. Pelle writes that images taken by N. Teamo
(0.41-m reflector at Punaauia, French Polynesia) on May 14.6 UT
show a diffuse coma of diameter 45" and a bright central
condensation.  S. Nakano reports that CCD images taken by Y. Ikari
(Moriyama, Shiga-ken, Japan, 0.25-m reflector) on May 14.8 show a
coma of diameter 15" and a short fan tail in p.a. 240 deg.  E.
Guido and G. Sostero write that co-added unfiltered exposures
obtained remotely with a 0.25-m reflector near Mayhill, NM, U.S.A.,
on May 15.4 show a sharp central condensation about 8" in diameter,
surrounded by a faint, extended coma about 25" in diameter (total
mag 15.5) and a fan-shaped tail 30" long toward the southwest.  J.
E. McGaha (Tucson, AZ, U.S.A., 0.36-m reflector) reports that his
four stacked 60-s exposures with on May 15.4 show a round coma 14"
in diameter with a tail 48" long in p.a. 242 deg.

     2008 UT             R.A. (2000) Decl.       Mag.
     May  14.46025   22 43 56.00   +10 47 48.4   15.5

The available astrometry, the following preliminary parabolic
orbital elements, and an ephemeris appear on MPEC 2008-J78.

     T = 2008 Apr. 22.838 TT          Peri. =  16.385
                                      Node  = 299.274   2000.0
     q = 2.05912 AU                   Incl. =  45.904


COMET C/2007 W1 (BOATTINI)
     Additional visual total-magnitude and coma-diameter estimates
(cf. IAUC 8899, 8931):  Apr. 13.82 UT, 8.6, 4'.2 (W. Hasubick,
Buchloe, Germany, 10-cm refractor); 23.88, 7.6, 15' (J. J. Gonzalez,
Leon, Spain, 10x50 binoculars); 30.93, 7.3, 12' (A. Amorim,
Florianopolis, Brazil, 10x50 binoculars); May 2.44, 6.9, 18' (S.
Rae, Tauranga, New Zealand, 10x50 binoculars); 6.00, 7.0, 25' (M.
Goiato, Aracatuba, Brazil, 7x50 binoculars); 8.45, 6.4, -- (D. A.
J. Seargent, Cowra, NSW, Australia, naked eye); 12.02, 6.5, 15'
(Amorim; moonlight); 14.96, 6.2, 23' (Goiato; moonlight).

                      (C) Copyright 2008 CBAT
2008 May 15                    (8945)            Daniel W. E. Green